Diese Datenbank enthält über 40.000 Dokumente zu Themen aus den Bereichen Formalerschließung – Inhaltserschließung – Information Retrieval.
© 2015 W. Gödert, TH Köln, Institut für Informationswissenschaft / Powered by litecat, BIS Oldenburg (Stand: 28. April 2022)
1Vakkari, P. ; Huuskonen, S.: Search effort degrades search output but improves task outcome.
In: Journal of the American Society for Information Science and Technology. 63(2012) no.4, S.657-670.
Abstract: We analyzed how effort in searching is associated with search output and task outcome. In a field study, we examined how students' search effort for an assigned learning task was associated with precision and relative recall, and how this was associated to the quality of learning outcome. The study subjects were 41 medical students writing essays for a class in medicine. Searching in Medline was part of their assignment. The data comprised students' search logs in Medline, their assessment of the usefulness of references retrieved, a questionnaire concerning the search process, and evaluation scores of the essays given by the teachers. Pearson correlation was calculated for answering the research questions. Finally, a path model for predicting task outcome was built. We found that effort in the search process degraded precision but improved task outcome. There were two major mechanisms reducing precision while enhancing task outcome. Effort in expanding Medical Subject Heading (MeSH) terms within search sessions and effort in assessing and exploring documents in the result list between the sessions degraded precision, but led to better task outcome. Thus, human effort compensated bad retrieval results on the way to good task outcome. Findings suggest that traditional effectiveness measures in information retrieval should be complemented with evaluation measures for search process and outcome.
Themenfeld: Retrievalstudien ; Suchtaktik
2Huuskonen, S. ; Vakkari, P.: Students' search process and outcome in Medline in writing an essay for a class on evidence-based medicine.
In: Journal of documentation. 64(2008) no.2, S.287-303.
Abstract: Purpose - The aim of this study is to explore to which extent searching by medical students in Medline produces information items useful for writing an essay measured by precision and relative recall as perceived by the students, the proportion of cited items, and their utilization on four dimensions of the essay writing task evaluated by external assessors. It also aims to study interrelations of search process and outcome. Design/methodology/approach - The study subjects were 42 third year medical students attending a class on Diagnostic and therapy. Searching in Medline was a part of their assignment of essay writing. The data consist of students' printed logs of Medline searches, students' assessments of the usefulness of the references retrieved, a questionnaire concerning the search process, and evaluation scores of the essays given by the teachers of the class. Pearson correlation coefficients were calculated for answering the research questions. Findings - The paper finds that precision and relative recall were not associated with evaluation scores in three of the four dimensions assessed. Some of the process variables were associated with precision and with assessment scores in two of the four dimensions assessed. Citing rate was negatively associated with recall. It seems that precision and recall are only weakly, if at all, associated to the use of information in the documents retrieved for writing the essay. Precision and relative recall are not associated to the way information in the retrieved items is used for performing the task. Users evidently look for a sufficient number of documents containing enough information for progressing in their task. Precision and recall are not sufficient measures in evaluating IR systems, but they have to be completed by other measures indicating the impact of the system on users' task performance. Originality/value - The paper provides useful information on students' information search process.